Japan Mycoremediation Part 1 // 金子 真司, Shinji Kaneko, professor at Yokohama National University has explored the decontamination of forests in Fukushima, contaminated with radioactive cesium (Cs) following the Fukushima Daiichi nuclear power plant accident.
While decontamination efforts have focused on residential areas and agricultural land, forests, covering vast areas and posing limited human exposure risks, have been largely left untouched. Existing decontamination methods, including phytoremediation (absorption by plants), have proven inefficient and impractical due to low transfer factors and high costs.
Fungi, when grown on organic matter have been observed to accumulate radiocesium in their biomass. The method entails cutting down forests, chipping the trees, and spreading the chips on the forest floor, allowing fungi to thrive. Once grown, the chips are removed, taking the radiocesium with them.
Field tests have shown that this method can achieve a decontamination efficiency of around 7%, significantly higher than phytoremediation. The research suggests that fungi, with their mycelium, can efficiently collect radiocesium distributed in soil without altering the soil structure. This approach offers a practical and gradual decontamination method while maintaining forestry practices of logging and renewal, with potential applications for other contaminated forested areas.
Further research and field tests are needed to optimize chip shape, tree species, and the duration of chip placement, considering various environmental factors. The results of these tests could be incorporated into forestry practices and provide a promising solution for forest decontamination in areas affected by nuclear pollution.
森林と放射性物質シリーズ:金子 | 水利科学 No.360 2018
Full paper available for download below.
Photo credits: Arkadiusz Podniesinski (1. Abandoned vehicles 2. Contaminated radioactive topsoil)